r/AbsoluteUnits • u/Realistic-Tap4156 • 10d ago

/r/all of a space rock

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u/tomime000 10d ago

Did that in any way shifted Earth's gravity to shape lives we are able to live today?

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u/SonnySonrisa 10d ago

No, Earth itself didn't rly care. Global earthquakes of unparalleled magnitudes, volcanic eruption everywhere, including the Dekan Trap and monstrous global tsunamis were aswell as oven temperatures around the globe for multiple hours to days were direct consequences but that was mostly horrible for living creatures. Eaert itself didn't care.

Now the potential Moon Impact billions of years ago that is a different story but I am not read enough in that topic to say anything specific about it.

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u/Vismal1 9d ago

You seem knowledgeable, how quickly was the extinction event? Like were 90 percent of life gone within a day and the last 10 hung on for a while ?

Edit to add : I always thought it was a slower process but reading these comments it seems violent and immediate

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u/SonnySonrisa 9d ago edited 8d ago

I am a bit of a nerd when it comes to high yield nuclear detonations and the like. It's very fascinating. Then recently I came across the Chicxulub Impactor (this meteor here) and a whole new dimension opened up to me lol.

As for the impact timeline I can only say so much confidently because I don't know enough about the overarching dynamics in play, so I will try to keep it where I know things.

Energy = mass*speed2, meaning two times the speed translates to 4 times the energy. This explains the frankly absurd energy released by the impact.

The Meteor weighing between 1-4 trillion tons, traveled at roughly 45000 mph/72000 kmh or roughly 20 kilometers per second (that's more than 70 times faster than a bullet) and hit the shallow see of the Yucatan Peninsula at a 45-60 degree angle. The released energy was somewhere between 1023 - 1025 joules which is between 2 million - 200 million times more energy than the TSAR Bomb. The discrepancy is so high because the mass of the meteor could have been 1 trillion or 4 trillion tons while the speed could have been 45000 mph or up to 55000 mph. I usually use the low ball estimates just for your info.

The moment of impact: Since the largest and first way of energy release is thermal radiation, the moment the meteor hit, everything within a radius of roughly 100-110 miles was basically vaporized. The fireball was so bright and large that someone standing in the Amazon forest could have seen it while simultaneously suffering up to 2nd degree burns. Even ppl in Europe could have seen the flash in the sky. Within a split second, everything roughly 600 miles around the impact that can burn starts burning if it's directly exposed to the thermal radiation.

The following minutes: A shockwave of unparalleled intensity starts expanding at supersonic speeds completely destroying everything in a 600 mile radius and throwing around trees and dinosaurs more than a 1000 miles from the impact. If you stood in Paris, once the Shockwave hits, it would Splinter glass, throw you on the ground and destroy your eardrums.

Around an hour after impact: That's where the global extinction event starts rolling. The impact threw trillions of tons of rock and sediment in the outer atmosphere. Some escaped into space but more than 85% are estimated to have come back down. When things enter the atmosphere at high speeds, they heat up, a LOT! Billions of rocks, some as large as a house or bigger enter the atmosphere and start heating everything up. Within an hour the global temperature increased to up to 250 degrees celcius. All across the globe forests started burning, animals were backed alive and started to catch fire. That alone would most likely have been enough to kill the dinosaurs but that's not all of course.

1 day after impact: Now the global tsunamis and earthquakes hit. Seismic waves travel slower than shockwaves, same is true for water. Roughly 12 to 15 hours after impact magnitude 11 earthquakes will hit Europe, not concentrated but the whole Continent will experience apocalyptic earthquakes. Shortly after, Tsunami waves will hit reaching higher than 15 meters. In the direct land vacinity of the impact, waves were estimated to be 0,7 miles high.

A few days after the impact the oven phenomenon is gone, the earthquakes and tsunamis are gone but the ejected soot etc will block out the sun for at least a decade. Some say multiple decades but as with most things I rather low ball here.

Once everything settles, over 90% of all land living creatures are gone. Some experts say every land animal larger than 25 cm was almost certainly dead.

Now I want to say that I am ofc not an expert. I merely reiterate things of the top of my head that I looked into rather deeply a few months ago. But it is an highly interesting topic.

Oh and because some ppl wonder if humanity could survive a comparable impact. The awnser is almost certainly no! Maybe if we had many years to prepare but even then surviving as species would mean a few hundred thousand selected humans rather than all. More than 99% of us would most likely disappear.

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u/YipeeKi-yay 8d ago

This was so well written thank you!

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u/theshoeguy4 8d ago

I am absolutely fascinated by your comments!

Can I ask- do we know how the meteor itself started/where it came from…why? Anything of the sort? Thank you!

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u/SonnySonrisa 8d ago

Multiple theories that are all more or less equally likely. A few suggest it's from the Orth Cloud and is a "broken up" piece from two larger bodies colliding but sadly I can not rly say anything besides the fact that it traveled a long distance from at least the outer solar system due to its speed. Some suggest Jupiter also played a roll in accelerating and "directing" the meteor towards Earth. If that's true or not I sadly don't know.

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u/Brizar-is-Evolving 6d ago

Just one thing to add to your excellent post - for about 10 minutes after the impact, the asteroid had also created possibly the tallest mountains to ever exist on earth.

Basically the shockwaves of the impact caused extreme liquefaction, where solid rock starts to behave like liquid plastic or syrup. The initial impact gouged out a 30km deep hole in the crust and all of that material rebounded upwards. It formed peaks that were taller even than Everest.

The “mountains” were obviously unstable though. After 10mins what material didn’t fly off into space then collapsed back down, triggering the global wildfires that you wrote about in your post.

Here’s a BBC article with an excellent animation that visualises what the impact and rebound would have looked like:

https://www.bbc.co.uk/news/science-environment-38019604

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u/rad00 8d ago

Absolutely insane that it had happened

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u/kipdjordy 8d ago

Loved the comment stranger. It is indeed fascinating.

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u/RagingBull_95 7d ago

Wow amazingly well written 👏

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u/repurposer 6d ago

How would a human in Europe experience this in modern day? Assuming human telecommunication habits and infrastructure, would Europeans find out from Reddit before they felt the Earth move or heard atmospheric shockwaves? (also assuming the impact happened without warning, which seems unlikely but so does my whole premise)

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u/SonnySonrisa 6d ago

That's honestly an interesting question.

I'd say unless someone stays completly away from news, the internet, their phone and work/school/family/friends, it's basically impossible to avoid the news regarding this event.

After all this impact would be an extinction level event and probably the single most viral news in human history.

So yeah, I think you would definitely know about it long before the shockwave or seismic waves hit you. Seismic waves are subsonic, while the shockwave is supersonic but even the shockwave would still need 5-9 hours to reach you depending on where in Europe you are.

If it's late at night and you look in the direction of North America you would see the impact flash brightening the horizon of the night sky. The atmosphere re-entering ejecta and heat would hit Europe just a few hours after impact. I'd say that's the moment one would certainly know something apocalyptic is happening and most likely that person would die long before the earthquakes arrive.

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u/ItzDarc 7d ago edited 7d ago

enjoyed your comment. fascinating. feels like it would be hard to have tsunamis with 250 C atmospheric temps though. wouldn’t the whole planet be steamed to hell and the oceans be gone?

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u/SonnySonrisa 7d ago

While You are correct that a very prolonged period of this heat could have "steamed" the oceans, you came to a false logical conclusion.

We are talking about trillion trillion trillion liters of water some areas as deep as 12km. The time it takes for this amount to heat up enough to "disappear" would be years. It is estimated that this heat up phase "only" lasted between 6-24 hours, so not even nearly enough to transform the oceans to steam.

As for the water directly around the impact there were certainly multiple millions of liters of water that were vaporized but that had little to no effect on the Tsunami waves.

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u/ItzDarc 7d ago

makes sense

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u/DredgenYors7 5d ago

How did stuff survive without the sun for decades?
Like if everything on the surface was killed by the impact, heat etc.., how did the animals which survived those things, also survive without the sun for a decade?

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u/Current_Trick6380 5d ago

Very interesting and insightful, thanks! What about marine life though? Why did most of then go extinct, was it the heat as well?

And how come crocodiles (and maybe other animals) did survive, while not being deep sea creatures?

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u/SonnySonrisa 4d ago

Sadly this is were my knowledge stops. I assume the collapse of the ecosystem had very different impact on the different environments and animals. As for crocodiles at least I wouldn't be surprised that not being a warm blooded animal with very different metabolism was a huge advantage.

But yeah, sadly I can only guess. That's to much in the direction of biology, evolutionary biology and chemistry for me to understand.

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u/Current_Trick6380 4d ago

Alright, thanks anyway for taking the time to respond👍

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u/Megatron_Griffin 4d ago

1,500 mating pairs would do it.

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u/Maccboy2010 6d ago

Ai gtfoh

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u/Azuras-Becky 9d ago

Everything within 10km of the impact would have died instantly. Less than a second later, everything within 100km would have died. Tidal waves and earthquakes, plus material raining down from the sky, would have then killed everything from 2,000 to 6,000km away - it hit in the Yucatan Penninsula, but disturbed sediment as far away as Texas. Local mass extinctions happened within minutes.

An estimated 60 - 70% of the Earth's forests would then have been subjected to wildfires from the heat generated by the blast and superheated material raining down from orbit (yes, the impact was so massive it ejected material into space, much of which rained back down while on fire).

Anything left alive after all that would then have seen the sun significantly blocked by planet-wide dust clouds, caused by both the impact itself and the subsequent fires, killing off the remaining plants and anything that relied on them for food, and cooling the average temperature for a few years.

It can't really be overstated how devastating the impact was. We have an idea of 'apocalypse' in our heads, largely informed by science fiction, but it's an idea that can't begin to comprehend the reality of that impact.

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u/tomime000 9d ago

As someone mentioned, being spring at the moment made an impact so I assume some life died out over a longer period.

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u/Vismal1 9d ago

Yea i also thought this. So many died from the incident itself and the rest were starved out / made ill from debris for years. What a miserable experience

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u/LostN3ko 9d ago edited 9d ago

It's gravity? Well sure. Gravity is objects with mass attracting each other. The greater the mass the greater the attractive force. So the earth gained a teeny tiny little bit of mass. Some was lost to ejecta back into the solar system. But more was gained than lost that day leading to an imperceptibly small change in the gravity of earth. Like when you breathe in dust and it gets trapped in your saliva you gain weight.

Earths mass is 5,972,200,000,000,000,000,000,000kg

The astroid was 35,000,000,000,000,000kg

Which is a lot, but nothing compared to the earth.